Gel Composition and Strength Properties of Alkali‐Activated Oyster Shell‐Volcanic Ash: Effect of Synthesis Conditions

摘要: The gel composition and mechanical properties of alkali-activated oyster shell-volcanic ash were investigated at different NaOH concentrations (8, 12, 15M) curing temperatures (60°C 80°C) in wet dry conditions. XRD, FTIR, SEM-EDS, TGA-DSC used for microstructural characterization the binder. system was found to be influenced by concentration not affected when temperature varied from 60°C 80°C. main phase N,C–A–S–H all ash, with C–S–H as secondary some samples contains high percentage iron. splitting υ3 = 1400–1494 cm−1 on FTIR spectra corresponded elimination degeneracy due distortion CO32− group. degree indicated that this carbonate group is linked Ca2+. compressive strength formation a phase. condition increased roughly between 28 180 d samples, while condition, partial dissolution Si–O–Si bonds silicate phases resulted reduction strength.